What landscape will you plant first? High veld, tropical, or desert? This will determine the enclosure, open or closed, and how much sunlight and water it needs.
Choose a glass large enough for your hands, tall enough for plants to grow, and spacious enough for vapors to evaporate and condense.
3.) Air Ratio
70% air, 30% soil is the ideal ratio. Overplanting a terrarium can cause mold. Allow plants space for air to circulate.
4.) Soil Layering
Layering soil is functional, not pretty. Pebbles, activated charcoal, then soil. Pebbles prevent water from spoiling, activated charcoal filters it, and soil captures heat for evaporation.
5.) Water Cycles
As night falls, water from the glass’s condensation sinks to the bottom with the pebbles. Why use pebbles? As the sun rises, the temperature rises and water rises through the activated charcoal, soil, and plants, evaporating along the glass roof until sunset. Then, repeating.
6.) Secret Ingredients
There are some ingredients that experienced terrarium builders use to keep soil healthy, and help plants grow better.